They also check on refrigerated containers to ensure they are working and maintaining the required temps for whatever is inside.
Here’s another plug for that book. If you’re at all interested in ships, this is good stuff.
When a ship is at sea there is no need for two licensed officers on the bridge. There will be one.
One would figure, the more modern the ship the greater the automation and the more likely to have less-maintenance materials.
US Flag ships.
Ships now days have very small crews 20 two 30. They are divided into 3 departments. Deck, Engineering, and Radio. The Deck department is under the Captain and would also include the cooks. The Engine department is under the Chief Engineer. And the radio department might be only 1 man.
Engine room Watches are 4 hours on 8 hours off. On each watch would be a licensed engineer and an oiler. Use to be the thirds would stand the 12;00 to 4:00 and the 8:00 to 12:00 watches, and the second the 4:00 to 8:00 watches. The First would be incharge of day work. That is repairs to engineering spaces. Also if the ship had refrigerated containers there would be a refer third. The refer third wold do any repairs and keep track of temps of the containers.
Off watch for exercise you can walk the deck. read books, play cards, or do day work for the 1st at the overtime rate. 1st wanted me to change a mast light at sea on a old T2, I passed on that job until we got into port.
All this can change on some of the new ships because they have no man enginerooms. Then there is only day work done and no watch standing.
And then there is comming inot port. Then along with the watch officer in the engine room will be either the chief, first, or both…
The cooks will provide 3 meals a day for the crew.
The deck crew will be standing watches and checking cargo along with the never ending painting or chipping. Ever been in a engine room with steel plate sky lights? When the deckies are running deck crawlers (neumatic chippers) over them it is unbareable.
I was on a USN fast attack submarine for several years, so I don’t have any firsthand knowledge of civilian ships. I always assumed they would have tiny crews, consisting of only the personnel necessary to keep the ship running and safely on course. Navy crews are set up to do a number of quite different things, depending on the vessel: engage the enemy, launch planes, follow & surveil other ships, fuel other ships, carry troops, etc. My Division Chief (who erroneously thought of himself some type of “badass”) once told us “Civilian ships are out here to make money, we’re here to make dead Russians.” (Shudder)
If you want an unparalleled, insider look at the life of a container ship and it’s crew, check out the Chief Makoi series on YouTube. They are fantastic.
How was life on the Indy other than your DC?
And the bigger the ship, the more automation to be maintained.
Looking at pictures of the Emma Maersk, I couldn’t help thinking how thankful the owners must be that modern lighting does not require as frequent bulb replacement. That looks like it would have been a full time job back in the 70’s.
Gotta say, that’s mighty generous of the officers. 
As noted above, painting does not start or end, it just IS. Every ship is painted constantly. When a section has been completely painted, the crew starts at the next section, scrapes all the rust and old paint, then paints that section. When the ship has been completely painted, it is time to begin the process all over. Recreation depends on the personal interests of the crew, but the internet and proliferation of electronic media makes it a lot more interesting than waiting to get close enough to a town with TV broadcasting as we did 48 years ago. On our boats (lakers get called boats even though they are ships in size) there were 3 deckhands and 3 deckwatch my first summer and 3 deckhands and a bosun my second summer, so painting a 700+ foot vessel with cabins (inside as well as outside) and vents and bollards and hatches etc. was pretty much a forever job.
As a total aside this reminds me of what I read about the very first computers. I think it was ENIAC but may have been one of a few others…
Their memory circuits were vacuum tubes. The tubes were arranged into racks of eight (I think). Each tube had a failure rate that was not bad but when you had thousands of them there was always one going bad every few minutes. They had a staff of people whose job was to run around and replace those on a non-stop basis.
IIRC Google had this same issue with their big data centers. A given hard drive may have a 30,000 mean time between failure rate (MTBF) but when you have 50,000 hard drives in one place it means there are always some failing at any given time. So, you need people to run around non-stop replacing those.
Same with the lights on a really big ship.
Randall Munroe (he of XKCD fame) cites a spec that says Google loses a hard drive every few minutes:
Based on what you all have said in this thread, there HAS to be a horror movie set on a shipping container, right?
Not a horror movie but I have seen a few movies where the hero wakes up, thinks they are finally out of trouble, only to walk out a door/container to find themselves on a cargo ship in the middle of the ocean.
Wasn’t there a movie about some guy in that type of situation, but it turned out to be a floating prison or something? I want to say it had Nicholas Cage in it but looking through his filmography nothing is ringing a bell. I guess that’d be one way to ensure nobody escaped.
Face off had Cage escape from an offshore oil platform/prison. I think there may have been something similar on one of the 24 episodes.
Escape From Emma Maersk with Snake Plissken?
The best container ship thriller is Alien. I suspect if it was available, most sea-going container crews and their employers would opt for spending most of their time in suspended animation.